Recent article in Warmbloods Today magazine referencing Dr. Clabaugh and Aramat Farm.

1. How Slow Do Warm
I
magine the scene: Two young horses that are the same
age are playing happily in a lush pasture. One, a two- • The coffin bone solidifies at birth
year-old Arabian, looks well on his way to physical • The short pastern fuses between birth and six months of age
maturity as he cruises around the field. The other, a • The long pastern fuses between six months of age and one year
two-year-old Warmblood, has longer legs, trips easily and • The cannon bone fuses between eight months and one year
appears somewhat awkward as he tears up the turf. and a half
Many Warmblood enthusiasts will agree that their • The small bones of the knee fuse between one and a half years
horses mature slower than other breeds of horses. But and two and a half years
what do veterinarians and researchers have to say about • The bottom of the radius and ulna fuse between two and two
this theory? Warmbloods Today recently set out to find the and a half years
facts on Warmblood development. • The weight-bearing portion of the radius fuses between two
and a half and three years
Is There Proof? • The humerus fuses between three and three and a half years
According to Dr. Kelleyerin Clabaugh, DVM, an equine • The scapula fuses between three and a half and four years
practitioner and owner of Aramat Farm, a sport horse • The hock fuses around four years of age
breeding farm in Oregon that specializes in raising and • The tibia fuses between three and three and a half years
training three-day eventers, there are many opinions • The femur fuses in three stages between two and a half and
about Warmblood development, however there is three and a half years of age
“surprising little fact or research about the matter.” • The pelvis fuses between three and four years of age
“I do not know of any study that states that light boned • The vertebral column fuses when the horse is five and half years of
horses are done growing by X years and Warmbloods are age, with male horses often taking up to six months longer
done by Y years,” she says. “Genetic lines, not just breed,
dictate growth potential and duration. Nutrition and According to one leading equine orthopedic researcher,
exercise also play a role in bone development.” Dr. Sue Dyson, it’s generally accepted that physes (growth
In fact, one researcher, Dr. Deb Bennett, PhD, founder plates) close later in non-Thoroughbred breeds when
of the Equine Studies Institute, has compiled a “growth compared to Thoroughbreds, “but most will be closed
plate conversion schedule” which establishes the typical radiologically by five to six years of age at the latest. The
times at which certain growth plates within the body distal radial physis is often the latest to close (in the lower
converts into stable bone. Dr. Bennett’s timeline is general limb), but whether this is a site of later growth or it is other
for all horses and is as follows: parts of the skeleton, I don’t think anyone knows.”
Two-year-old Hanoverian gelding Baccarat (Bugatti Hilltop x Cor Noir)
bred by Crossen Arabians & Warmbloods. He won numerous breed
show awards including the 2011 NEDA Year End Awards-1st place for
two-year-olds in the Breeding Division. Photo courtesy Susan Crossen
48 March/April 2012

2. bloods Grow? By Erica Larson
The mare Beaujoulais (Oldenburg by LeSanto) (1 & 2) at 35 months at Flying Lion Farm. (3) At 36 months they put Beaujoulais into work.
A different mare at Flying Lion Farm, Isabella (Oldenburg by LeSanto) that they felt needed more time to mature. Here (1 & 2) she too is 35 months
old. (3) At 44 months they began Isabella under saddle. Photos courtesy of Flying Lion Farm
Scientifically, there may be no specific proof that and physically to go to work. Every one is different.”
Warmbloods grow slower than other breeds. However Juliana Whittenburg of Flying Lion Farm in central
many breeders that produce Warmbloods as well as other Florida breeds Thoroughbreds for racing as well as
breeds say there’s plenty of anecdotal evidence that Warmbloods for sport. She notes that a lot of trainers
Warmbloods mature later than other breeds. will start Thoroughbreds at one and a half which, in
“It can vary for each individual horse, but in general her opinion, is way too soon. For the most part their
Warmbloods mature later than our Arabs, therefore we farm starts their Thoroughbreds in light work at age two,
start them later,” says Tom Crossen of Crossen Arabians & and she believes that the Thoroughbreds mature and
Warmbloods in Coventry, Connecticut. Tom and his wife finish growing at around age four.
Susan have been breeding horses for 25 years and started When it comes to her Warmbloods, Juliana agrees with
with Arabians, have bred Arab/Warmblood crosses, and Tom Crossen. “Every horse is an individual,” says Juliana.
today they are breeding Hanoverians and Oldenburgs “One Oldenburg mare that we bred was started at three
along with their Arabians. and she was ready to go into steady work. For the larger
As the farm’s trainer, Tom remarks, “I can begin Warmbloods, we often wait until they are three and a
ground work and regular round pen work with our half or four before putting them into regular work. We’ll
Arabians usually at around two and a half to three, but the break them earlier, but then wait. Chances are they are still
Warmbloods are started later at three or three and a half growing at four and need that extra time to mature.”
or maybe even four, depending on the individual horse’s
balance and/or mental maturity.” Growth Factor
Initially Tom puts a young Warmblood in the round pen When discussing equine growth and maturity rates with
to assess whether the horse is ready to focus. “I can tell clients, regardless of what breed of horse they own, Dr.
very quickly whether the horse is mature enough mentally Clabaugh uses an analogy of an oak tree and a pine tree:
(Continues on p. 52)
Warmbloods Today 49

3. (Continued from p. 49)
“You want your horse’s bones to be strong and dense Nutrition for Healthy Development
to withstand compressive and tensile forces. Oak trees One of the most important areas for juvenile horse owners
grow slower than pines but if you ever watch an oak tree to evaluate is the food their young horses consume. As Dr.
in a hurricane it can twist and bend in the wind without Clabaugh explains, certain factors in a young horse’s diet
breaking. The pine tree breaks every time.” can either help or hinder their physical development.
Dr. Clabaugh explains that the biomechanical “As the gastrointestinal tract matures and the skeletal
composition of young horses differs from that of adult system develops, most adult horses are able to meet their
horses. “The juvenile’s joint responds to biomechanical energy requirements with good quality roughage alone,”
loading (exercise) by developing increased collagen cross- she says. “But growing horses, particularly growing horses
linking resulting in improved tissue quality and injury in consistent work, require additional amino acids and
resistance. This ‘functional adaptation’ is crucial early in life nutrients provided by concentrates.”
as the joint loses its adaptability after five to nine months Many feed companies produce special feed for young
of age.” and growing horses. Dr. Clabaugh explains that these
Dr. Clabaugh references a 1999 study by Barneveld feeds typically contain the appropriate trace minerals
and van Weeren that concluded that this biomechanical and vitamins for the juvenile horse. “Due to the nutrient
loading was both beneficial and necessary for the proper variation in grass versus legumes, concentrates are
development of the equine locomotor system, but designed to be fed with either grass hay or an alfalfa mix.”
she also cautioned that exercise should be carried out What type of hay is best for a growing horse is often
carefully in juvenile horses. a topic of contention amongst breeders and owners, but
“I advise all my clients to strategically exercise Dr. Clabaugh explains that juvenile horses can develop
(controlled conditioning and turnout) their horses starting properly on either grass hay or legume roughage (such
from birth,” Dr. Clabaugh relays. “Conditioning programs as alfalfa). “Many of my clients mistakenly assume that
should allow for adequate alfalfa is ‘better’ than grass
downtime for bone hay with regard to protein
remodeling. It is important quality and caloric density,”
to remember that the she says. “It is true that good
skeletal system must be quality alfalfa is better than
developed first and the average grass hay but often
muscle system later.” To good grass hay is better
this end, she suggests the Left: Commonly used plants for hay include mixtures of grasses than average alfalfa. Without
such as ryegrass (Lolium species), timothy, brome, fescue, Bermuda
skeletal system is “best grass, orchard grass, and other species, depending on the region.
having each roughage
stimulated by very short Right: A high-quality mix of grass and alfalfa (legume) hay. analyzed, it is not possible to
work periods on firm tell quality visually.” Next she
footing followed by free exercise on soft footing.” cautions, “It is not advised, however, to feed straight alfalfa
She also cautions against excessive longing or round to growing horses as alfalfa may interfere with calcium
pen work for young Warmbloods and adds that repetitive retention.”
circles compress one surface of the joint and strain Dr. Clabaugh also stresses that a nutrient balanced
the opposite stabilizing structures which could lead to diet promotes growth over weight gain: “One study found
developmental problems for the juvenile horse. that horses eating only oats and alfalfa got fatter, while
When starting a juvenile Warmblood under saddle, Dr. those eating a balanced concentrate along with alfalfa
Clabaugh stresses that moderation—not the age at which gained more height.” This is an important point to consider
the horse is backed—is key. “Musculature is necessary to because as Dr. Clabaugh explains, overweight juvenile
support and stabilize joints and the larger breeds are often horses can develop some developmental disorders.
still filling out as 4-6 year olds,” she explains. “Jumping is “A horse can be overweight but have good bone
not detrimental as long as it is not excessive. Repeatedly density. If, however, the horse is being fed only for weight
jumping an underconditioned horse will increase the gain and not structural integrity, then DOD is more likely
likelihood of degenerative orthopedic disease (DOD) to occur. Weak, fibrous bone will not be able to support
including epiphysitis, osteochondrosis, juvenile arthritis the additional weight. As long as the diet is balanced,
and degenerative soft tissue disease.” a horse can be fed to promote rapid growth without
Dr. Clabaugh notes that there’s no hard and fast “recipe” negative consequences.”
when it comes to starting a Warmblood under saddle, but Finally, are supplements important for growing
encourages owners to ensure the horse has developed horses? “As long as you feed a concentrate designed to
appropriately before starting intense training. complement your roughage source, you should not need
52 March/April 2012

4. to add additional nutrients or minerals in the form of a “I recommend taking survey radiographs (X rays) prior
supplement,” she says. to commencing training,” she says. “If OC is diagnosed
early, surgical debridement is often curative.”
What Can Go Wrong?
As previously mentioned, young horses are at risk of In Conclusion
several developmental orthopedic disorders including: Surprisingly, there is little scientific research focused on
Epiphysitis—Also known as physitis, epiphysitis is the the growth rate of Warmblood foals and juvenile horses
inflammation of growth plates (the areas within the bones as compared to other types of horses. There is a large
of young horses from which the bones grow or lengthen). body of anecdotal evidence and a common belief that
The most common points affected by epiphysitis are just Warmbloods mature slower than other types of horses.
above the knee, the cannon bones, and the lower tibia; When it comes to a young Warmblood, as with any
Osteochondrosis—Osteochondrosis (OC) results from breed, it’s important to treat each horse as an individual
a disruption in the growth of articular (within the joint) and address any unique needs as they may arise. If
cartilage. The most frequent joint affected is the hock; questions should arise about the physical maturity of
Juvenile Arthritis—Not surprisingly, juvenile arthritis is a certain horse, consulting a
simply arthritis that develops in juvenile horses; and veterinarian is the best way
Degenerative soft tissue disease—A condition to determine if a particular
that affects horses of all ages, degenerative soft tissue feeding regimen, training
disease occurs if a horse is not adequately conditioned, program or exercise routine
developed, and fit, then he is more likely to overuse his is beneficial or detrimental to
tendons and ligaments. Chronic overuse can result in the horse.
degenerative suspensory disease, bowed tendons and Dr. Kelleyerin Clabaugh and “I am considerate of each
Gryph. Photo © James Forester
collateral ligament desmitis according to Dr. Clabaugh. horse’s individual physical and
The majority of the aforementioned ailments develop mental condition when determining the extent and scope
within the first few years of life. Dr. Clabaugh notes, however, of exercise and competition,” Dr. Clabaugh says. “My focus
that OC can develop as late as four to five years of age. is my horse’s long term health and performance.”
Warmbloods Today 53